UCD9081: After programming, click shutdown, MON5 and MON6 always have a level, about 1.9V, why

These are all the configurations.

This is what happens when I click shutdown:

• Here's my schematic:

  

• This is the level state of MON6 input after clicking shutdown:

  

• MON6 input voltage power-on waveform:

  

• MON6 input voltage off waveform:

  

When I power off the board and restart it, after clicking on the EVM to find the device, the MON5 and MON6 configurations of the device were changed by themselves:

I have disconnected all the voltage to MON and do not input PFM, this level has always existed, please help to analyze why, please reply, thank you very much

Hi

There are couple things to check:

1. what's the status of the ENABLE signal of the MON5/6? they shall be de-asserted so that the downstream POL is off

2. you have to check whether there is any leakage path to drive those rail.

Regards

Yihe

thank you for response

When I hit shutdown, all EN is off,level 0V, and MON5 and MON6 external access circuits are disconnected，so I think that level was generated inside the chip UCD9081.

Hi

That is impossible that UCD can have such leakage on those two pins.

Do you check the PA_5V and PA_3V3 after the shutdown?

Regards

Yihe